Apparatus for the ignition of mercury vapor rectifiers



Aug. 30, 1932. .1. .JQNAS 1,873,963

APPARATUS FOR THE IGNITION OF MERCURY VAPOR RECTIFIERS Filed Aug. l, 1928 By Q? Patented Aug. 30, 1932 rrrENtfl JULIUS JONAS,l or BADEN, SWITZERLAND, `ASsIcrNoE y To AKTIENGESELLSCHAFT BROWN EovEEI & CIE., 0E BADEN,A SWITZERLAND, A JoiNT sTocxcoMPANY or SWITZERLAND i APPARATUS non THE IGNITION o F MEECUBY vAroE EECTIEIEES Application led August 1, 1928, SerialifNo. 236,698, and in Germany August 8, 1927.

This invention relates to improvements in devices for igniting or starting the operation of mercury-arc electric rectifiers.

rlhe ignition of mercury-arc rectiliers 1s 5 generally accomplished either by plungingl 10 igniting devices have disadvantages from the viewpoint of design or because theycreate obstacles in the operation of the rectifiers. Such disadvantages are obviated, in the present-invention, by establishing a momentary mercury cathode without movement of either the anode orof the entire device.

` Among the objects of the present invention is the provision of an ignition device forl A further object of the invention is to pro# vide an improv-ed igniting device forrectiers in which a jet of mercury, under pressure,

is projectedfrom the cathode into momentary Contact with an ignition anode adjacent thereto.

Other objects and advantages will hereinafter appear. j For the purpose of illustrating the invention, several embodiments thereof are shown in the dra-wing, wherein Figure 1 is a central vertical sectional view of a mercury-arc rectifier embodying the present improvements;

Fig. 2 is an enlarged detail sectional view taken from Fig. 1; and

Fig. 3 is a view similar to Fig. 2, illustrating a modication. Y Referring more particularly to Fig. 1, the Vvrectifier includes a wall 10, a top covery member 11 and a bottom 12.A

The top 11 is provided with the usual condensing chamber 13 and with suitable anodes contact between the ignition ,anode and the 14 and 15. An ignition anode 16 i as shown and is supportedfin any suitable manner in proximity to a mercury cathode 20. f. vThe'bottom 12.*is .provided with a central aperture 17 which` is surrounded-.bye wall 18 of insulating material which, in vconnection with a plate 19, forms a well arranged to receive the mercury cathode 20.r j

Arranged in suitable position, exteriorly of the rectiiier and adjacent to the cathode 20, is a. cylinder 21 formed of non-magnetic material which is unaected by mercury. The cylinder 21 is providedwith an aperture 22 in the portion adjacent' the cathode 20 and is arranged to receive mercury therefrom.

The cylinder 21 is surrounded by a coil 23 arranged about one end thereof and connected througha Switch 24 with a suitable source of current 25. j j Y A piston or plunger 26 floats upon the mercury within cylinder' 21 and is guided iny its movement Vby the wall of the cylinder. -V The plunger 26 is provided with` a central aperture 27 and is formed of magnetic material to permit actuation thereof upon excitationv of coil A tubular connection 28 extends from closely adjacent the bottom of cylinder 21 through plate 19` into cathode 20. The tube 28 extends through aperture 22 of the cylinder 21 and aperture 27 ofthe plunger 26 which is guided thereby. The tube 28 may he formed from tantalium, tungsten, -molybdenum or some other fusion-resisting material in case it is'found that desirable result-s are'secured by extending the tube beyondthe sur- Y face of` cathode 2O to serve as a point of at-l tachment for the arc when the lrectifier is in operation.

The tube is provided with'apertures 29, and' theend thereof extending into the rectifier is constructed to form avnozzle portion 30.

The operation of the device is as follows: The switch 24 is closed to effect Yenergization of coil 28. Current flowingthrough the coil 23 attracts and depresses the'plunger oroperating member 26 which is accordingly moved downwardly to displace thel mercury vin cylinder 21 andr force the same upwardly through connection 28, the mercury previously in connection 2 8 being thereby ejected s disposed Y from nozzle 30 into contacting relation with ignition anode 16. As the mercury jet falls back into cathode 20, an arc is struck and a portion of the mercury volatilized. The mercury vapor thus formed p rovides a current path between anodes 14 and 15 and cathode 2O which permits current impressed on the anodes to How to the cathode. After the mercury has been ejected from cylinder "21, switch 24 is opened. A portion of the cathode mercury will drain through apertures 29 into tube 28 from which mercury will flow into cylinder 21 and float plunger 26 into its original position. I

In the modification illustrated in Fig. 3, a tube 31 extends into the mercurycathode. The lower exterior end of tube 31 is connected in circuit with the heating current 25 by the vswitch 24. rlhe upper end of tube 31 isprovided with a funnel-shaped exhaust nozzle 32 Vwhich is-preferably formed of fusion-'resisting materials and is provided with apertures 33 for a purpose which will hereinafter appear.

In operation, switch 24 is closed and the mercury in' tube 31 heated to the point of vaporization, at which time some of the mercury is ejected from nozzle 32 into contact with ignition anode 16, whereuponV the rectifier it put into operation as above set forth. The apertures 33 in the nozzle provide for return flow of the mercury into tube 3l. l

While only two embodiments of the invention have been shown and described, it will material enclosing a body of mercury and be understood that changes in shape,^size and arrangement of the parts maybe made without departing from the spirit of the invention or the scope of the appended claims.

1. In an igniting device for mercury-arc rectiers, a rectifier, means for enclosing a body of mercury, said means having a discharge orifice and refilling apertures, an anode adjacent the discharge orifice of said enclosing means, a floatingplunger within said enclosing means for producing pressure to expel mercury into contact with said anode. j

2gIn an igniting device for mercury-arc rectifiers, a rectifier, means lof non-magnetic provided with a discharge orificeand `refilling apertures, 'an anode adjacent the discharge orifice of said enclosing means, an electrically-operated plunger of magnetic material within said enclosing means for protact with said anode. i

3. `In an igniting device for mercury-arc rectifiers, a rectifier, means for enclosing a body of mercury, said means having a discharge orifice and refilling" apertures, an anode adjacent the discharge orifice of said enclosing means, a plunger within said enclosing means, and a coil arranged to de- Y said anode. Y

5. In an electric current rectifier comprising-a ,mercury cathode, an ignition anode, means supported partly above and partly below the surface level of the said cathode in fixed position with respect to the said anode, the said mea-ns'having al 'channel extending therethrough and terminating in an exhaust nozzleabove the surface level of thesaid cathode, means for expelling a portion of the said mercury through the said channel and nozzle into contact with the said anode, and i apertures in the first ysaid means beloww the surface level of the said cathode for automatically returning a portion of said mercury into the said channel following expulsions of mercury therefrom.

6. In an electriccurrent rectifier comprising a mercury cathode, an ignition anode,

Vmeans supported within thesaid cathode in a fixed position with respect to the said anode, the said means extending partly above Y and partly below thesurface level of the said cathode, a channel extending through the said means and terminating in a nozzle above the surface level of the said cathode,

pressure means for forcing portions vof said i mercury through said channel and said nozzle to initiate an arc between saidv anode and said cathode, and apertures within the first saidmeans below thesurface level of the vsaid cathode for automatically returning a portion of said mercury to said channel following expulsion of mercury therefrom.

In testimony whereof have hereunto subscribed my name this 13th day of uly A. D.

JULIUS JONAS.

Vducing pressure to expel mercury into con 

